The body of a 24-year-old woman has been found in a flat after a fire broke out on the 18th floor of the building.
Firefighters and police were called to the scene in the Maryhill area of Glasgow at about 0630 GMT.
The high rise block, in Glenavon Road, was evacuated and an investigation is under way, Strathclyde Police said.
The Scottish Ambulance Service sent three vehicles to the scene and an adult woman was taken to hospital, a spokesman for the service said.
He added: "One other female was treated for smoke inhalation and one woman was treated for a minor burn."
Det Insp Simon Midgley, from Strathclyde Police's Maryhill office, said: "Our investigation is at an early stage and we are working with our colleagues in Strathclyde Fire and Rescue to establish the exact circumstances surrounding the fire.
"It is too early to say whether the fire is suspicious and we do not wish to speculate on that until our investigation has concluded."
Anyone with information is asked to contact Strathclyde Police.